w203 Secondary air injection, does it run when its warm outside?

[Arzaam]

I have a 2002 m111 w203 and i noticed recently that I cannot hear the secondary air injection pump at all on a start since last few week , before i could hear it cycle on and off till it got unto operating temp. and recently there are high ambient temps in my area over 40C even at night. no check engine light, so I was wondering whether this is normal, car gets upto normal operating temp in a minute.

last year I had a airflow too low code for secondary air injection but check engine light never came on and dealer couldn't find anything wrong so they just cleared it though it used to come up every now and then as a stored code without making the light come on but now recently I can't hear the pump so was wondering if the temps had anything to do with it.

 

[hotrodder]

I'd say normal? Earlier MBs like my s124 use coolant temp as one of the main 'triggers' for the air injection pump... something along the lines of running the pump for X secs provided the coolant temp is below 40°C (or whatever) and engine speed is below a certain rpm etc

 

[Arzaam]

thanks! that makes sense.